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Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , David Hildenbrand , Mike Rapoport , Suren Baghdasaryan , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 01/39] mm/vma: fix mmap_prepare file handling, remove file_doesnt_need_get Message-ID: X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <179253282492.1207257.6426479952081115792.b4-reply@b4> X-Rspam-User: X-Rspamd-Queue-Id: 978B01C0005 X-Stat-Signature: iqnnq663961jpfqy8mffc9ha7k5yha93 X-Rspamd-Server: rspam01 X-Spam-Status: No, score=-11.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-HE-Tag: 1792593452-619021 X-HE-Meta: U2FsdGVkX18Q6lJUnUGqs2c4DWNQ0N0TEcUATxz+SLKqpLqf+wP/6OdlJyLZ7EDd7tFCSg0eXgshV/xluj0izzGIjGkrIXluddwH7jzPZlcTDdH/8JP5cu2pcID185Ddj6aUUcp08qpE6I+2gpEY2tEm51b9fXsTw0d3rF8i0oME3dq3WCVUP5usszDxvMjj2GXiBoujO8sPJBCK+lX8lAhmc7isYai2+h4Pg9I0I7zbdw5+NJovR8t7eXLtZDIk7dsNMCpLwhFHacxIEO2NeU7h8yDT15wBNdy9wwxTPcN5sLaovlrq8t0zyeH98AIPqdzyom9vOkNpv2IWNFWK6okcJ6VRumqcnW8cqgCrTAx45ypSOZGrFH38F1gRwm7W2fWKCN494nDZh9hpH1uT6UtRlB9mvChWltghMMFAzf4BXiTsK+e7kAZXHBY8edSkv4GEaa+AZ+tW2YVLm0OwJCoJSj8al8aIFmh935keVtVyQh+H4Ecrm5dxm/1OKU9lXj9VS5eQP/Lxd0+ihKn6vn8fEXL1nAPLppMxTPBQoMzI9G8gsfkM0fOYOFPpXpAUptUYyoABGWE9XjGNT88DKG/QLbDN/b3TVFMhzbzE7F6blLYdNJ75+7I7x3ne91ZmMIZOrB/oybsCmZr7LC2vGyTakOpDJW/m1tOQsoaIcqM9YU/Mge6dqH016scfYCQ7RXLSLP+loG5s1vO0afRig/T34oHpjbxEhJkV9eTabwwhU3EsEE/TtW2canATeRsUZxEr0vCI407fv3iK6sG8BqOHH2rgS6YQHaBFEsRuGAo4LwEl/9LjZ2qn2ibL8G3uOQDyyEh8YQbgbwXY1WfiOJqgTXzIg+bvKWQIvSGQmp+wMaE8eZsRFOKSLy0C7ZkG6hlgJUsT4XeO57zylYXX8eNn8TSQwrX7ggq302PHjN6xQfhMG2M06NwjH0tdPvYbp1QK6lytX+arm+t/UHs IJuscSsT nYOO3OyI6+R2Yly1DUlo4vRAROamXgwWopFKM1EyoHHWRuvwR8LzEBsg8X4OLVRb5x5QxgdGAF5Kb6odpSiK1+Y1Lhhcw3J/mYV/eIYVJXeQCGeJmgJ+ebF8yFKWdy8V0iciBnfjrHZhu9uPvwKme2h7dBMhEALHPqbjl64qTP0yYD6kyV2pfVsY+UnidiQc1rXuNCnxRjiD3rqdv0b4SRQOslmXaNOLK4Ti2mHgO43AYezC+pYWSzWpp9o6om4kLivGjnfM/ul/jurL4RzeC5ceVOKDHmecYCcBo4ckawuXt+4QcfvTx1xF3dBDpDNkzzKpflkRikwLt2SdhzcTjhs6JkSqel1a2njepHfPd4OegtGPi3oUJI3rWkN2rwWfwjvDqlnxJH3TANSX90gklnB2pFA== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 [ cut cc list for sanity ] On Tue, Oct 20, 2026 at 05:47:04PM -0400, Gregory Price (Meta) wrote: > On 2026-10-13 16:04 +0100, Lorenzo Stoakes (ARM) wrote: > > The map->file_doesnt_need_get flag is confusing and the existing > > implementation has holes. > > > > Drivers are permitted to change the owning file of a mapping. If they do > > so, they are required to take a reference on that file. > > > > The mmap() operation which ultimately invokes __mmap_region() is guaranteed > > to drop the refcount for the original file the mapping was made under, but > > this is not true for the replaced file. > > > ... > > > > Reviewed-by: Suren Baghdasaryan > > Signed-off-by: Lorenzo Stoakes (ARM) > > Have a nit below, but otherwise > > Reviewed-by: Gregory Price (Meta) Thanks! :) > > > +static bool map_same_file(struct mmap_state *map) > > +{ > > + return map->vm_file == map->file; > > +} > > > > Terrible function name :] I think let's leave things as-is and maybe chase this separately as a follow-up ;) -- Cheers, Lorenzo